A new Schiff base, 4-((1E,2E)-3-(furan-2-yl)allylidene)amino)-N-(5-methylisoxazol-3-yl) benzene-sulfonamide (L), was synthesized by thermal condensation of 3-(2-furyl)acrolein and sulfamethoxazole (SMX), and the furan Schiff base (L) was converted to a phenol Schiff base (L’) according to the Diels–Alder [4 + 2] cycloaddition reaction and studied experimentally. The structural and spectroscopic properties of the Schiff base were also corroborated by utilizing density functional theory (DFT) calculations. Furthermore, a series of lanthanide and transition metal complexes of the Schiff base were synthesized from the nitrate salts of Gd, Sm, Nd, and Zn (L1, L2, L3, and L4), respectively. Various spectroscopic studies confirmed the chemical structures of the Schiff-base ligand and its complexes. Based on the spectral studies, a nine-coordinated geometry was assigned to the lanthanide complexes and a six-coordinated geometry to the zinc complex. The elemental analysis data confirmed the suggested structure of the metal complexes, and the TGA studies confirmed the presence of one coordinated water molecule in the lanthanide complexes and one crystalline water molecule in the zinc complex; in addition, the conductivity showed the neutral nature of the complexes. Therefore, it is suggested that the ligand acts as a bidentate through coordinates to each metal atom by the isoxazole nitrogen and oxygen atoms of the sulfur dioxide moiety of the SMX based on FTIR studies. The ligand and its complexes were tested for their anti-inflammatory, anti-hemolytic, and antioxidant activities by various colorimetric methods. These complexes were found to exhibit potential effects of the selected biological activities.

The blood–brain barrier (BBB) serves as a protective barrier for the central nervous system (CNS) against drugs that enter the bloodstream. The BBB is a key clinical barrier in the treatment of CNS illnesses because it restricts drug entry into the brain. To bypass this barrier and release relevant drugs into the brain matrix, nanotechnology-based delivery systems have been developed. Given the unstable nature of NPs, an appropriate amount of a biocompatible polymer coating on NPs is thought to have a key role in reducing cellular cytotoxicity while also boosting stability. Human serum albumin (HSA), poly (lactic-co-glycolic acid) (PLGA), Polylactide (PLA), poly (alkyl cyanoacrylate) (PACA), gelatin, and chitosan are only a few of the significant polymers mentioned. In this review article, we categorized polymer-coated nanoparticles from basic to complex drug delivery systems and discussed their application as novel drug carriers to the brain.

This study examines the effects of the lactide/glycolide molar ratio on the synthesis of polymeric nanoparticles using a PVA-SDS stabilizers solution. PLA was obtained with a ratio of 100/0, while PLGA was synthesized at ratios of 88/12 and 64/36. Polymerizations employed ROP at 130°C with stannous oc-tanoate and 1-dodecanol as catalysts. Polymerizations were conducted through ring opening at 130°C with stannous octanoate and 1-dodecanol as catalyst and co-catalyst. Characterized polymers were used to pre-pare emulsions stabilized with polyvinyl alcohol (15 g/L) alone or mixed with sodium dodecyl sulfate of various molecular weights (MW=13-23, 31-50 and 85-124 KDa). These emulsions were stored in phos-phate-buffered saline for 28 days at 37.4°C. Colloidally stable emulsions were achieved using different poly (vinyl alcohol) concentrations, with the lactide/glycolide molar ratio influencing particle diameter. The elec-trostatic stabilizer formed by the poly (vinyl alcohol)-sodium dodecyl sulfate mixture demonstrated .Superior stabilization compared to poly (vinyl alcohol) alone, representing a novel finding. Moreover, the poly (vinyl alcohol-sodium dodecyl sulfate) mixture showed reduced water diffusion into the nanoparticles compared to poly (vinyl alcohol) alone, as evidenced by molecular weight and pH measurements. Addition-ally, the degradation of poly (lactic acid) and poly (lactic-co-glycolic acid) films was investigated; pH measurements in the immersed solutions showed that the degradation was increased with higher glycolide content.